The present invention relates generally to lead frames for use in integrated circuit packaging and more particularly, to a lead frame including a specifically constructed magnetic component, such as an inductor or transformer.
In integrated circuit packaging, a lead frame is used to support an integrated circuit within an integrated circuit package as well as provide electrically conductive leads for the connection of the integrated circuit to other circuit elements outside the package. In several types of circuits, it is desirable to provide a magnetic component in association with the integrated circuit. To date, the magnetic component, for example an inductor or transformer, has been formed as part of the integrated circuit or provided as a discrete component formed for use in surface mount or through hole circuit fabrication. Both of these approaches have certain limitations.
U.S. Pat. No. 5,070,317 discloses a magnetic device which may be incorporated into an integrated circuit. However, this approach has definite limitations. For instance, in the case of an inductor, the physical size of the integrated circuit limits the inductor to a relatively low inductance. Similar limitations apply to other magnetic devices. Therefore, in situations where a higher inductance or larger magnetic component is required, the magnetic component must be provided external to the integrated circuit.
There are many situations where larger magnetic components are required or where, for some other reason, it is not desirable to incorporate the magnetic device into the integrated circuit. In these situations, the magnetic component is typically provided in the form of a discrete component formed for use in surface mount or through hole circuit fabrication. This approach to providing a magnetic component associated with the integrated circuit also has some disadvantages. In some situations, the circuit may call for a component for which an off the shelf component is not readily available. Under these circumstances, a more costly custom component is required. Also, it is often desirable to include the magnetic device in the integrated circuit package. The present invention provides an integrated circuit package wherein the package includes a customized magnetic component that is produced, in part, along with and as a component of the lead frame of the package.